Light is a tag about anything generates photons in the visible spectrum
0
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1answer
51 views
Proximity Sensor [on hold]
I am trying to make a circuit that as an object moves closer to a proximity sensor it triggers a dimmer switch controlling a light and amplifier for loudspeakers.
Basically as an object moves closer ...
2
votes
3answers
129 views
PWM duty cycle vs candelas for LEDs
What is the functional relation between PWM duty cycle for LED and its luminous intensity (candelas)? Linear or not?
0
votes
1answer
65 views
How can I trigger a photography strobe from a iPhone LED flash?
I would like to trigger a photography/studio strobe flash based on the flash of an iPhone camera's LED flash. I'm picturing a device that I could attach to the back of the iPhone temporarily when I ...
3
votes
1answer
120 views
Will a incandescent burn out if you leave them on forever?
We've all had a time or too two that when you really needed light, and I mean need it immediately, and you flip on the switch, and with a pop and a bright flash, your incandescent is toast. However, I ...
2
votes
2answers
105 views
Alkaline cells vs. LED flashlight
I have (had, actually) an El Cheapo pocket LED flashlight powered by 3 AAA cells. It was shipped with very low quality "salt" cells (regular, low weight - someone please suggest a proper English name ...
0
votes
0answers
55 views
LED Lighting Forward Voltage Constant Current
I have a qty of 6 7W led luminaires that would normally use individual 350mA drivers.
I am looking to use one driver to supply all 6.
However, I understand that the forward voltage of 20V per ...
0
votes
1answer
126 views
How to power “arduino” from wall?
So I have a fake "arduino" that I put together (The main components on a breadboard, i.e. ATmega328, capacitors, ocilator, etc) and I am trying to use it to overide a light switch (When the light ...
2
votes
1answer
70 views
Creating an LED array light box
I'm wanting to make a light box of sorts from LEDs and wanted to run it by you to confirm I have the right idea...
I have ordered 500 super bright LEDs off eBay and want to wire loads of them ...
2
votes
2answers
195 views
Energy-efficient LED driver circuit
I want to light a normal LED for as long as possible on two AA or AAA batteries. It does not have to blink or so, just stay on. The LED doesn't have to light at the max, as long as it's visible from ...
1
vote
2answers
253 views
How can I power the blue LEDs separetely on this aquarium light?
I have a Beamswork LED aquarium light like this. It has a 3 way switch:
All LEDs off
Blue LEDs on only
White AND blue LEDs on
It has a single mains power plug.
What I want to do is make it have ...
2
votes
2answers
637 views
How much can I safely plug into a light socket converted to a standard outlet?
I just moved my office desk from our extra bedroom on to our stairway landing. The tricky thing was that there was no wall outlet to plug anything into. However, there was a nearby light socket, ...
0
votes
1answer
177 views
Light bulb exploded [closed]
This morning, one of the lights in my house began to flicker. I didn't think much of it, and left the room to get a drink. While I was in the other room, I heard a bang, and came back to find broken ...
3
votes
3answers
154 views
How to switch light on by standing on a mat
I'm working on a project for school. And I have this dance matt. As long as you stand on that matt the light should go on and stay on until you step off the matt again. But I have no idea how to make ...
0
votes
1answer
166 views
virtual light communication
I have to design a project that uses an LED to transmit data and a LDR to receive the data or signal from the LED. But the problem is I have to use two Arduino UNO boards, one for LED transmit and ...
8
votes
3answers
904 views
Continous light - do LED s flicker like fluorescent lights?
Continous light - do LED s flicker like fluorescent lights?
Under flourescent light there is a flicker.
As i understand LED work only with DC current, thus they have a AC to DC transformer circuit ...
-6
votes
1answer
58 views
Ceiling light holder [closed]
I touched the wires of a ceiling light holder with plyers, it made a spark and all of the power in my room was gone. WHAT DO I DO?
-1
votes
1answer
126 views
LED RGBW Lighting, Will this Design work?
I've got this schematic for a very small lighting setup for my basement. The goal is to have two fixtures that have red, green, and blue lights that can be controlled with knobs on a Separate ...
37
votes
6answers
6k views
Does turning a lighbulb on and off repeatedly use more energy than just leaving it on for hours?
Let's say I have a 60W bulb in a lamp in my bedroom. If I kept the lamp on for 2 hours straight but the next day, I switched it on and off 10 times in intervals of 5 minutes. Which scenario would use ...
7
votes
2answers
375 views
How to start with creating a device?
I have recently wondered if I could build some kind of useful and cool device, using some sensors, transmitting signal and doing something with it - I think people who answer questions on this site ...
4
votes
2answers
628 views
Basic circuit to keep LED either on or off depending on night/day
How can I have a LED either on or off (not in between) depending on night or day with basic electronics? I have created the circuit below, but it only shines and in darkness it dims.
The ...
0
votes
2answers
487 views
Do dimmer switches work properly with any kind of lamp? [closed]
I have a dimmer switch installed in my room that I like very much, but lately incandescent lamps became harder to find, and soon (in a few years or so, if I'm not mistaken) they will be gone to be ...
0
votes
2answers
224 views
LED brake lights - detecting voltage drop?
I am trying to light up some LEDs on my Rustler VXL RC car only when braking/reversing.
I found out that on my receiver I have three wires: black(-), red(+), white(+). The one that interests me is the ...
1
vote
1answer
974 views
Building a 3x3x3 LED cube?
I need to built a 3x3x3 LED cube. I need to be able to turn every LED on (not at the same time) in different patterns. I need to use Charlieplexing (note that any other method is not a viable ...
7
votes
2answers
218 views
What factors affect the brightness of electroluminescent wire?
I'm interested in experimenting with creating my own electroluminescent (EL) wire. I've seen some videos on creating your own by Jeri Ellsworth. I have a few additional questions.
I understand that ...
6
votes
1answer
287 views
Solid state relay for home lights application
My application is controlling home lights. I want to use relays to switch lights on and off. My circuit should work on all kind of lights such as neon lights, halogen lights, strobe lights and others. ...
2
votes
2answers
227 views
A christmas light bulb question
This may look like a homework, but it's not. Actually it is related to Christmas. My Chrismas lights in front of the house are constructed from segments. Each segment consists of 16 incandescent light ...
3
votes
3answers
115 views
What lamps are out there that don't flicker and give off warm light (like incandescent)?
In the past few years several countries stopped producing 100W incandescent lamps, and in a few years they may disappear to be succeeded by fluorescent lamps. I really don't like the flicker and the ...
6
votes
2answers
794 views
Dimmer to bulb control
I need to control a bulb of 220V, with different intensity light levels.
I've an Arduino Uno Board, which receives a variable voltage from a Light-to-voltage converter (TSL12S) (Like a ...
9
votes
1answer
2k views
How do the lights on stairs work?
I remember that there's a very simple circuit diagram that explains how there can be 2 light switches for 1 light and that regardless of which switch you turn 'on/off' the light is toggled on/off.
...
2
votes
1answer
163 views
Light switch setup for bedroom [closed]
on my bedroom I want to put two 220V lights on the side of my bed, and I want to control them with 3 switches:
the main switch is beside the door, and will commute both lights on and off.
two ...
1
vote
1answer
530 views
Use 3.5V power LED connection on motherboard to control a 12V lighting accessory in a computer case?
Background for the problem:
I rebuilt my computer in a new case where the components fit a bit better. Everything is great, and I have no issues with it. However, because of the way they engineered ...
5
votes
2answers
238 views
light system for stairs
I have a stair made of several steps. I want that when I put a foot on a step, the light of the next step is turned on. Each light is placed just under the edge of the step. If I use LEDs as lights, ...
0
votes
1answer
122 views
Low Voltage Photosensor
I'm looking for a photosensor/photo IC part (combination of photodiode, linear amplifier, Schmitt trigger and output transistor) that can be powered with 3.3V. Fairchild QSE256/257/258/259 is almost ...
2
votes
3answers
265 views
using led stripes with external battery: any side effects?
i have to power some led stripe from ikea with a drill battery:
On led stripe power is written: 12V 0,25A. and on drill power: 12V 2A.
Now i want to power n led strip (for example: n=4) and i ...
1
vote
2answers
182 views
Do I need to solder on my DE2 board to replace a broken segment?
I've already posted a question here about this when I realized that all things were not right with my Altera DE2 board:
Is this display broken or is it a bug?
After verifying that the segment indeed ...
7
votes
3answers
263 views
How can I achieve very bright light?
I'm not sure if this is right site for this, but couldn't find better.
I've been given an task to create something that has light intensity like police beacon. I need it to be cheap, so I'm looking ...
3
votes
2answers
132 views
Identify a light emitting component
here's a picture of component that is not a LED but emits light, it's a tiny glass light bulb with a resistor and a red plastic case for mounting it.
6
votes
1answer
202 views
Designing a wide-range light detector circuit
I'm looking for a few hints in designing a light detector circuit.
Priorities are that the circuit is simple (both as in few parts and as in relatively easy to understand), rather cheap, and can ...
0
votes
1answer
295 views
how many light bulb for one relay?
i've just done this tutorial: http://www.arduino.cc/es_old/Tutoriales/Rele
it works great! i've done it in a breadboard (with two 5v circuits for test) and then soldered (for just does not have 220v ...
4
votes
1answer
188 views
ambient light rejection in absorbance sensor
I'm making a sensor to measure light absorbance in a sample where the geometry varies over time.
I found a very nice transimpedance amplifier, the AD8304 designed for use with PIN photodiodes with a ...
5
votes
1answer
271 views
What type of method for producing White-Light LEDs is the most common?
There are two primary ways of producing white light-emitting diodes (WLEDs):
To use individual LEDs that emit three primary colors red, green, and blue and then mix all the colors to form white ...
3
votes
1answer
238 views
Power Off Delay circuit
I'm looking for a timer that starts when power is removed.
Here is the use case:
The head light on dirt bike my turns off with the engine.
This good when it's parked.
This is very bad when doing ...
5
votes
2answers
1k views
Powering 10watt light bulb for 24 hours using solar power
I am a total noobi to solar power and even electricity so I appologies if I am asking a silly question.
Imagine I have a 10watt light bulb which I want to leave on for 24 hours a day. Will I just ...
4
votes
1answer
706 views
How to find Emitter and Collector of an LDR
How can we find the emitter and collector of an LDR. I am using it in the following circuit but I don't know how to identify which terminal of the LDR is emitter or collector.
Here it is mentioned ...
7
votes
2answers
2k views
LM358 (Op-Amp) For a Light Sensor?
I'm looking at this light sensor:
What exactly is the point of having an LM358 (a Dual Op-Amp I believe) for a Light Sensor?
Maybe I'm missing something....but what exactly purpose does it serve?
...
-1
votes
1answer
86 views
12 VDC Power to Illuminated Button
I want to hook up a push button on my photobooth following this guide.
I already have a serial cable and a port on my machine. The button I will be using is this one here.
It is an illuminated ...
4
votes
2answers
308 views
What type of LED lights are needed for detecting retro-reflective markers for motion capture project?
I've a project in which I want to add 10-12 led lights around webcam's lens so that the camera can detect retro-reflective tape in it's viewing area.
How this process works is something like this. ...
3
votes
2answers
344 views
Power LED light from battery when mains fails
I'm attempting to design a circuit for some LED lighting that will be powered from a mains connected 24V DC transformer but if the power fails then the a battery should take over as the power source ...
0
votes
1answer
370 views
How to operate tube-lights using relays
I am using the circuit mentioned in one of the articles of EFY (Ref.) .I have added the freewheeling diode across the relay, and I am able to turn On/Off bulbs as well as CFLs successfully.Now I want ...
3
votes
2answers
160 views
How to measure, with timestamps, changes in the received luminance?
I'm working on a project that is in need of some testings to validate it. I need to make some readings of luminance from a light source and store this reading with a timestamp (milliseconds ...
